My company spent over a billion dollars just to rewrite a C++ project with a lot of technical debt in C++. We are finally making money after the rewrite, but that was a lot of cost and I honestly cannot recommend it to anyone.

I lean to what I'm trying to figure out how to do now: how do I rewrite the small parts that change the most into something else while keeping the whole working all along. Best part is other people are already at different points in the journey and we don't have to all move at once, nor pay the price all at once.